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CryptoHack

A free, fun platform for learning modern cryptography

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Learn By Doing

Learn about modern cryptography by solving a series of interactive puzzles and challenges. Get to know the ciphers and protocols that secure the digital world by breaking them.

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Level Up

Earn points by solving challenges. Finish categories to earn trophies and gain levels to track your progress. Can you reach the top of the scoreboard?

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Fresh Challenges

We are constantly creating new challenges to keep your crypto knowledge up to date. Expect exciting brainteasers and whole new categories as the site continues to grow.

New Challenges
ECLCG (HITCON CTF) CTF Archive 0
Sus (ImaginaryCTF) CTF Archive 0
Share (HITCON CTF) CTF Archive 0
Leet Universe (ImaginaryCTF (Daily)) CTF Archive 0
Hyper512 (HITCON CTF) CTF Archive 0
Weekly Top Users
#1 AurtharPaul 3840
#2 Haritha 2750
#3 d3vboi 2640
#4 comeon 2335
#5 B00177224 2235
Recent Solves
Lemur XOR ElChals
Bytes and Big Integers yoshy8654
Bytes and Big Integers szymoszer
Secure Protocols LFM023
Finding Flags cyb3rgh0u1
Recent Solutions
Cofactor Cofantasy lsamc 0
Greatest Common Divisor yanis_k 0
You either know, XOR you don't yanis_k 0
Extended GCD code_syl 0
Greatest Common Divisor code_syl 0

Level Up

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